Classifications

• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05B—SEWING
  • D05B1/00—General types of sewing apparatus or machines without mechanism for lateral movement of the needle or the work or both
  • D05B1/08—General types of sewing apparatus or machines without mechanism for lateral movement of the needle or the work or both for making multi-thread seams
  • D05B1/18—Seams for protecting or securing edges
  • D05B1/20—Overedge seams
• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05B—SEWING
  • D05B65/00—Devices for severing the needle or lower thread
• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05B—SEWING
  • D05B29/00—Pressers; Presser feet
  • D05B29/06—Presser feet
• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05D—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES D05B AND D05C, RELATING TO SEWING, EMBROIDERING AND TUFTING
  • D05D2303/00—Applied objects or articles
  • D05D2303/08—Cordage
• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05D—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES D05B AND D05C, RELATING TO SEWING, EMBROIDERING AND TUFTING
  • D05D2305/00—Operations on the work before or after sewing
  • D05D2305/08—Cutting the workpiece
  • D05D2305/10—Cutting the workpiece longitudinally

Definitions

• the invention relates to a sewing method and a sewing machine for sewing, on a sewing piece such as a flexible cover, of a sewing point formed of threads, called auxiliary threads, of the type forming a passage s' extending in the direction of sewing (overlock, zigzag, ...), with a thread, called tension thread, guided and placed relative to the stitch in the passage simultaneously with the stitching of the auxiliary threads, so that this tension thread can slide longitudinally and / or laterally in this passage, the tension thread not being pricked by the auxiliary threads forming the stitch.
• EP-0 223 312 and US-4 732 097 describe a method and a sewing machine making it possible in particular to sew an overlock using auxiliary threads, and to guide and place a tension thread in a passage of this overlock , simultaneously and as the seam is sewn.
• the overlock must be sewn out of the workpiece around the tensioning thread over lengths corresponding to said strands protruding from the tensioning thread to be left free, and these are released and cut. unnecessary excess overlock portions after sewing and clearing the workpiece from the machine.
• sewing excess portions of overlock without sewing piece corresponds to abnormal operation of the machine, source of malfunction, interruption of production rates, and adjustment, or even deterioration of the machine (in particular feed dogs in direct contact with the foot in the absence of material).
• the assembly of tension thread and overlock cannot be guided, downstream of the stitching means, with the same precision as a piece to be sewn.
• auxiliary threads separate from the tension thread, this tension thread not being an auxiliary stitching thread, and not being stitched, that is to say crossed by the auxiliary threads.
• the passage for the tension wire can be formed (much less efficient but sufficient in certain applications where the tension wire does not undergo or undergoes little tension) by a zigzag point.
• tension wire thus covers any threadlike element (including cord, cord, cord, braid, loop %), elastic or not, separate from the auxiliary threads used to form the stitch, which is guided and placed in the passage simultaneously with the stitching of the stitch without being crossed by the auxiliary threads, so that it can slide longitudinally and / or laterally in this passage.
• the invention therefore aims to propose a solution to the above-mentioned problems, and aims to propose a sewing method making it possible to form, at the start of sewing, and / or in the current part of sewing, and / or at the end of sewing , strands of tension thread disengaged from the passage formed by the stitch - in particular strands protruding beyond the ends of the passage formed by the stitch -, in a simple, rapid and reliable manner.
• the invention aims in particular to propose such a method which can be implemented in a fully automated manner, under the control of a programmed control device (robot, automaton, computer system, etc.) without requiring human intervention.
• the invention thus aims to allow the production, in particular fully automatically, of strands protruding from a tension thread at the start and end of sewing at each end of a passage of a sewing point such as a overlock in which the tension thread is placed simultaneously with the stitching of the stitch, so that it can slide longitudinally and / or laterally.
• the invention also aims to allow the production, in particular entirely automatically, of loops of the tension thread released from said passage in the current seam portion.
• the invention aims in particular to propose such a method which allows the complete automation of a method of covering an object, such as a seat cover, with a flexible cover, as described by EP-0 223 312 and / or US-4,732,097.
• the invention aims in this regard to allow productivity gains, savings in labor and raw material.
• the invention also aims to make it possible to achieve the aforementioned aims in a simple and economical manner using a simple and inexpensive modification. supplied to a known sewing machine, in particular an overlock machine as described by EP-0 223 312 and / or US-4 732 097.
• the invention therefore also aims to propose a sewing machine allowing the implementation of a method according to the invention.
• the invention aims more particularly to propose such a sewing machine which can be obtained by means of a simple modification made to a known sewing machine, in particular an overlock machine as described by EP-0 223 312 and / or US- 4,732,097, after manufacture.
• upstream and downstream are used with reference to the direction of sewing by the stitching means of the machine, and to the direction of driving the workpiece by these stitching means which is therefore driven from upstream to downstream.
• the direction of sewing and driving the piece is assumed to be horizontal, for reasons of clarity, although this arrangement, the most common in practice, is not strictly essential in the context of the invention.
• transverse displacement designates any displacement relative to the sewing and driving direction, having at least one component in a transverse plane perpendicular to the sewing and driving direction by the stitching means.
• lateral displacement is meant any transverse displacement also having at least one horizontal component, that is to say parallel to the workpiece and to the work-holding plate, or, in other words, orthogonal to the direction of displacement of a needle of the stitching means.
• vertical displacement means any displacement comprising at least one transverse component at least substantially perpendicular to the workpiece and to the workpiece carrier, that is to say in a plane defined by the direction and by the direction of movement of a needle.
• a transverse displacement can therefore be a lateral displacement without vertical displacement, a vertical displacement without lateral displacement, or a combination of a lateral displacement and a vertical displacement.
• switching and “stitching” and their derivatives are used, unless otherwise indicated, in the broad sense to designate the formation of any stitch with threads, without implying that all the threads actually cross the thickness of the sewn piece.
• switching means generally designates any means allowing a stitch to be made (within the meaning of the AFNOR NF G 05-002 standard, the terminology of which is adopted in the present application) with one or more threads , and includes in particular one or more needles and / or one or more hooks or loosers.
• the invention therefore relates to a method of sewing, on a workpiece to be sewn and in a sewing direction, of a sewing point formed of threads, called auxiliary threads, using the stitching means of a sewing machine , this stitch being of the type forming a passage extending in the direction of sewing, with a thread, called tension thread, guided and placed in this passage simultaneously with the stitching of the auxiliary threads, so as to be able to slide longitudinally and / or laterally in this passage, characterized in that at least a portion of the tension wire extending upstream immediately downstream of the stitching means is displaced transversely with respect to the stitching means, between a normal position for placing the tension thread in the passage and a position for disengaging said portion of the tension thread where it is inclined relative to the direction of sewing of the stitch, and passes, opposite the stitching means , e n outside the action area of the stitching means and outside said passage, to allow in particular the cutting independently of the auxiliary threads of the stitch and / or the tension thread by
• said portion of the tension thread is moved transversely during sewing from the sewing point by the stitching means, that is to say that the tension thread is moved between the normal position and the position released while continuing to sew the auxiliary threads by forming sewing stitches, without interrupting the stitching means.
• said portion of tension wire extends upstream and at least immediately downstream of the stitching means, avoids, by this fact alone, almost any risk of blockage of the tension thread by the auxiliary threads which cannot be stitched so as to pass through the thickness of the tension thread.
• the tension thread is released from the passage and the action zone of the stitching means when it passes opposite and in line with the stitching means. It is also possible to synchronize the stitching means and the transverse movement of said portion of tension thread to prevent this movement being carried out simultaneously with a downward movement of a stitching needle.
• a work plate which extends laterally from a motor frame of the machine.
• At least one guide piece - of the tensioning wire disposed upstream of the stitching means - is moved transversely.
• a guide piece is moved transversely which is distinct from a pressing member.
• This guide piece is for example formed of a guide eyelet, crossed by the tension wire, and disposed at the downstream outlet of the upstream pressing member.
• This embodiment is advantageously applicable to the second variant mentioned above.
• an upstream presser member carrying means for guiding the tension thread is moved transversely, and the workpiece is driven by a downstream drive member disposed immediately downstream of the stitching means.
• the upstream pressing member is in particular a crowbar and / or a rotary member (wheel, roller, roller, etc.) driven in rotation by a specific motor member or free in rotation about a transverse axis.
• the downstream drive member is in particular a downstream presser foot and / or a downstream rotary member, or a downstream drive shoe.
• This embodiment is advantageously applicable to the first variant mentioned above, to form strands protruding from the tension thread at the ends of the seam.
• the upstream pressing member is moved laterally outside the area of action of the stitching means, and outside said passage.
• the upstream pressing member is also moved vertically and upwards to avoid, in the release position, any contact of this upstream pressing member with the workpiece.
• the invention provides for at least partially sewing while the upstream pressing member is released and is therefore no longer applied in the functional position on the workpiece. It has indeed turned out, in practice, that this is possible without any difficulty, thanks to the downstream drive member which can drive the workpiece and / or the auxiliary threads forming the stitch and / or the tension wire avoiding any malfunction, and in particular any jamming phenomenon.
• an upstream pressing member can be moved to form strands that protrude the tension thread at the ends of the seam, and one can move laterally and / or vertically a separate guide piece of a pressing member (for example an eyelet to form loops of the tension thread released from said passage in the running part of the seam.
• said portion of the tensioning wire is moved laterally by a distance sufficient to clear and laterally distance the tensioning thread, on the one hand outside the area of action of the tapping means, and d 'on the other hand outside the area of action of a first knife for cutting the auxiliary wires disposed downstream - notably immediately downstream - of the stitching means.
• This first knife is used to cut the auxiliary threads from the stitch without the risk of cutting the tension thread simultaneously.
• the invention further relates to such a method suitable for allowing a strand of tensioning thread, called a protruding strand, to protrude beyond a start end and beyond an end end of the seam formed by the stitch, characterized in that, at the end of the stitch:
• the first cutting knife is actuated to cut the auxiliary threads from the stitch, and the stitching is interrupted by the stitching means
• the piece is moved downstream until a length corresponding to the sum of the lengths of the strands extending beyond the tension thread to be formed at the start and at the end of the seam, - the part of the tension wire to be cut is engaged to separate the end protruding strand of the workpiece and the beginning protruding strand of a next sewing piece, in a second cutting knife,
• said portion of the tension wire is replaced in the normal position before actuating the second cutting knife.
• a sewing machine designates any machine comprising at least one mechanism, known as a sewing head, incorporating sewing means (stitching means, work-holding plate, drive members, thread guide , ).
• a sewing machine consists of a supporting structure or frame, at least one sewing head mounted on the frame, drive motor means carried by the frame (in general at least one electric motor), and control means (pedal (s), button (s), automaton (s) or digital system (s) and / or computer system (s) ...) carried by the frame.
• the terms "sewing machine” can therefore denote either an isolated sewing head or a more complete assembly comprising at least one sewing head and other associated members as mentioned above.
• the invention also extends to a sewing machine - in particular a traditional sewing machine modified after its manufacture - for the implementation of a method according to the invention.
• the invention therefore relates to a sewing machine comprising means for stitching at least one sewing point formed of auxiliary threads on a piece to be sewn, in a sewing direction, this sewing point being of the type forming a passage s' extending in the direction of sewing, and means for guiding a thread, called tension thread, for its positioning in the passage simultaneously with the stitching of the auxiliary threads, so that this tension thread can slide longitudinally and / or laterally in this passage, characterized in that it comprises means, called means for releasing the tension thread, to move transversely relative to the stitching means, at least a portion of the tension thread s' extending upstream and immediately downstream of the stitching means, between a normal position for placing the tension wire in the passage, and a position for disengaging said portion of the tension wire where it is inclined relative to to the sewing direction and passes, opposite the stitching
• the tension thread release means are adapted to be able to move transversely at least said portion of the tension thread during sewing from the stitch by the stitching means.
• the invention also advantageously relates to a machine comprising a motor frame and a work-holding plate extending generally on one side of the motor frame from the stitching means, characterized in that the tension wire release means are suitable for laterally moving said portion of the tension wire on the side of the work-holding plate and opposite the motor frame, out of said passage, from the normal position to the release position.
• the invention also advantageously relates to a machine in which the stitching means comprise at least one needle, and comprising means for driving the sewing piece, characterized in that the driving means comprise at least one member, known as a downstream drive, arranged immediately downstream of the needle, and in that the release means tension threads are adapted to transversely move at least a portion of the tension thread extending upstream from the downstream drive member.
• the means for guiding the tension wire comprise at least one upstream guide part disposed upstream of the stitching means and carried by support means suitable for being able to place this guide part in the normal position. in which it guides the tension thread with respect to the stitch, or in the tension thread release position in which it is moved transversely with respect to the stitching means, so that these support means for the piece (s) (s) upstream guide act as means for releasing the tension wire.
• the means for guiding the tensioning wire comprise at least one double-acting actuating member - in particular a pneumatic cylinder or an electromagnet - making it possible to move the tensioning wire transversely between the tension wire release position, and vice versa.
• the means for guiding the tension wire comprise at least one lateral guide piece for the tension thread and means for supporting this guide piece with respect to a frame of the machine, and the means for supporting this guide piece are adapted to be able to place it in the normal position in which it guides the tension thread relative to the stitch, or in the position of lateral release of the tension thread in which it is moved laterally relative to the stitching means, so that these means for supporting the guide piece act as means for releasing the tension wire.
• the means for supporting an upstream guide piece are adapted to be able to place this guide piece in the normal position in which it guides the tension thread with respect to the stitch. , or in vertical release position tension wire in which the guide piece is moved vertically, in particular upwards, relative to the stitching means.
• the invention also relates to a machine comprising means for guiding the tension thread formed and / or carried by an upstream presser member for driving the workpiece, and means for supporting the upstream presser member with respect to a machine frame, adapted to apply, in the active position, the upstream pressing member in contact with the workpiece, characterized in that the support means are adapted to be able to place the upstream pressing member in the thread release position tension in which the upstream pressing member and the means for guiding the tensioning thread are moved laterally relative to the stitching means, so that these support means for the upstream pressing member act as means for releasing the voltage.
• said means for supporting the upstream pressing member comprise: - an arm articulated by a downstream end to the frame of the machine so as to be able to pivot around a vertical axis and around an axis horizontal transverse and carrying the upstream pressing member with the means for guiding the tension wire at its upstream end,
• actuating member carried by the frame and having an actuating rod movable in translation
• the connecting rod has a torsion so as to generate, from a translational movement accompanied by a proper rotation of the actuating rod, movements of lateral displacement of the pressing member upstream by pivoting of the arm around the vertical axis, and of vertical displacement of the upstream pressing member by pivoting of the arm around the transverse horizontal axis.
• the machine comprises a first knife for cutting the auxiliary wires, disposed downstream of the stitching means, and said tension wire release means are adapted to move at least said portion of the wire. laterally tensioning a sufficient distance to laterally release the tension wire from the first auxiliary wire cutting knife.
• the machine comprises two wire cutting knives, the first arranged downstream of the stitching means for cutting the auxiliary overlock threads, the second arranged downstream of the first at a corresponding distance to the length of a strand of tensioning thread, called a protruding strand, to be left beyond a start end of the seam formed by the stitch on a next piece of sewing.
• the first knife is disposed immediately downstream and near the downstream drive member.
• the machine comprises means for automatically guiding the piece to be sewn relative to the guide means and, where appropriate, to the cutting knife (s), and means automatic control of the tension wire release means and, if necessary, of the cutting knife (s).
• the means for automatically guiding the workpiece comprise a gripping robot adapted and programmed to move the workpiece on a work holding plate of the machine as the execution of the sewing.
• the means for automatically guiding the workpiece and the means for automatically controlling the tension thread release means comprise a programmable digital system adapted and programmed to control, as and when sewing is carried out. , the stitching means, the movements of the workpiece, the tension wire release means and the sectioning knife (s).
• the execution of the seam according to the invention can be entirely automatic and can be part of an automatic process for dressing objects such as seat upholstery.
• the invention is more particularly and advantageously applicable to the execution of a stitch which is a stitch, in particular an overlock with one, two, three, four or five sewing threads (auxiliary threads).
• the machine according to the invention is then advantageously an overlock machine, in particular an overlock stitching and shaving machine.
• the invention automatically allows, during sewing, to release the tensioning thread sliding out of the passage formed by the stitch, and to replace it there in normal position to form either loops of tension thread released from the passage in the running part. , or strands of ends of the tension wire beyond the ends of the passage.
• the loops in the current part allow for example the attachment of the tension wire on hooks or studs of an object to be trimmed and / or to exert a tension in the current part of the edge of the part.
• the end strands are used to exert traction on the tension thread and to block the tension thread in the stretched state. It should be noted that the formation of these loops and / or these end strands does not deprive the tension wire of its possibilities of sliding in the passage. Indeed, the invention makes it possible to prevent the tension thread from being crossed and blocked by the auxiliary sewing threads.
• the invention further relates to a method and a machine characterized in combination by all or some of the characteristics mentioned above or below.
• FIG. 1 is a partial schematic perspective view of a machine according to the invention in the normal position of the tension wire
• FIG. 2 is a view similar to FIG. 1 illustrating the machine in the disengaged position of the tension wire
• FIGS. 3 to 9 are partial schematic views from above illustrating different stages, in chronological order, of a method according to the invention.
• FIGS. 10 and 1 1 are partial schematic front views illustrating the means for releasing the tension wire in the normal position and, respectively, in the released position, of a machine according to the invention
• FIGS. 12 and 13 are partial schematic views from above illustrating the means for releasing the tension wire in the normal position and, respectively, in the released position, of a machine according to the invention
• - Figure 14 is a schematic view partial side illustrating the stitching means and the release means of a machine according to the invention
• FIG. 15a is a schematic view in axial section of the specific means for guiding the proper rotation of the actuating rod of the means for releasing the tension wire of a machine according to the invention
• FIG. 15b is a view similar to FIG. 15a, shown without the actuating rod,
• FIG. 16 is a partial diagrammatic top view of a machine according to the invention
• FIG. 17 is a diagrammatic perspective view of an overall automatic machine according to the invention
• FIGS. 18 to 20 are partial schematic views from above respectively illustrating two alternative embodiments of the release means of the tension wire of a machine according to the invention.
• FIG. 20 - Figures 21a, 21b and 21c are partial schematic views in vertical cross section illustrating the tension wire release means respectively in the vertical release position, in the normal sewing position, and in the lateral release position, of the machine according to the invention in accordance with the variant of FIG. 20,
• - Figure 22 is a partial schematic side view illustrating the stitching means and the release means, in the vertical release position, of a machine according to the invention according to the variant of the figures 20, 21a, 21b and 21c.
• the sewing machine according to the invention shown in the figures is a shaving serger sewing machine, that is to say a machine adapted to cut the edge of a piece 1 to be sewn (flexible cover of fabric, leather, of synthetic or other materials) using a side knife 2, and perform an overlock stitch 3 with auxiliary threads 4 for sewing.
• auxiliary threads 4 transparent nylon threads (330 deniers) of small diameter or any other industrial sewing thread can be used.
• EP-0 223 312 and US-4 735 097 the content of which is incorporated by reference into the present application, already describe the general characteristics of such a sewing machine and of the process for covering objects, such as linings seats, which can be implemented using such a machine. Consequently, only the characteristics specific to the invention which is the subject of the present application will be detailed below.
• the sewing machine comprises means 5, 6, 7 for stitching, which in the example shown, are formed by a needle 5, an upper looper hook 6, and a lower hook 7. These means 5 to 7 of stitching make it possible to make a three-thread overlock stitch.
• the invention nevertheless also extends to any other overlock point, the machine also being equipped with stitching means corresponding, or more generally, to any stitching point making it possible to produce a longitudinal passage P in which a separate tension thread 8 auxiliary threads (that is to say that is not one of the threads forming said stitch) can be introduced, this tension thread 8 being able to slide longitudinally and / or laterally in the passage P.
• the thread tension 8 can be formed of a nylon thread, or of a cord or cord, or of an elastic thread or the like.
• the sewing machine also comprises means 9 to 10 for driving the piece 1 to be sewn. in and through the stitching means 5 to 7.
• the machine essentially comprises a motor frame 12 and a work-holding plate 13 extending generally on one side of the motor frame 12 from the stitching means 5.
• the drive means 9 to 11 drive the part 1 in a direction of seam D which extends along the side of the motor frame 12 from which the work-holding plate 13 extends laterally.
• the drive means 9 to 11 comprise a set of motorized lower claws 9 (that is to say driven by a motor of the machine) passing through the work-holding plate 13 by suitable lights, an upstream pressing member 10 disposed above the work-holding plate 13 upstream of the stitching means 5 to 7 for applying the piece 1 to be sewn against the lower claws 9, and a downstream drive member 11 disposed above the door plate -work 13 immediately downstream of the stitching means 5 to 7 for driving the piece 1 to be sewn after stitching.
• the upstream pressing member 10 is a traditional crowbar.
• the downstream drive member 11 shown is a motorized upper claw synchronized with a portion of the lower claws 9 disposed downstream of the stitching means 5 to 7.
• the downstream drive member 11 can also be formed by a simple presser foot which presses the part 1 on the lower claws 9.
• the side cutter 2 extends immediately upstream of the stitching means 5 to 7 for cutting or shaving the edge of the piece 1 before the overlock stitch is executed.
• the upstream pressing member 10 carries a guide piece 14 of the tension thread 8.
• This guide piece 14 is, in the example shown, in the form of a section of bent tube extending on the side of the foot of doe 10 oriented towards the motor frame 12, so that the tension thread is guided immediately upstream of the stitching means 5 to 7 parallel to the sewing direction D, in the axis of the passage P produced by the stitch of overlock.
• the tension wire 8 is brought to the guide part 14 from a reserve reel by at least one guide member 15 secured to the motor frame 12.
• the machine also includes a first sectioning knife 16 (for example a knife reference C-GEX T07, sold by the company C-GEX SYSTEM 'S (France)) placed immediately downstream of the drive means 9 to 11 and means 5 to 7 for stitching, namely immediately downstream of the downstream drive member 11.
• the machine also includes a second knife 17 (for example an offset knife sold by the company C-GEX SYSTEM'S (France) ) sectioning disposed in the axis of the first knife 16 in the sewing direction D, downstream, at a distance dl from the first knife 16 corresponding to the desired length for a strand 18 projecting the tension thread 8 to leave free beyond an end 19 at the start of the overlock stitch 3.
• a first sectioning knife 16 for example a knife reference C-GEX T07, sold by the company C-GEX SYSTEM 'S (France) placed immediately downstream of the drive means 9 to 11 and means 5 to 7 for stitching, namely immediately downstream of the downstream drive member 11.
• the machine also includes a
• Each of the sectioning knives 16, 17 is motorized by means of an actuating motor member 20, respectively 21, which may be a pneumatic cylinder, an electromagnet, or any other similar actuating member.
• Each knife 16, 17 is for example made up of a movable blade which can pivot around an axis parallel to the sewing direction D, and a fixed blade extending at the level of the work-holding plate 13 in the direction transverse by crossing the sewing direction D.
• the movable and fixed blades act like scissors to cut the threads which pass over the fixed blade, the movable blade being driven to pivot downwards.
• the upstream pressing member 10 with the guide piece 14 is carried by support means 22, 23, 24 which include an arm 22 articulated to the frame 12 of the machine, an actuating member 23 with double action (this is ie capable of being controlled in two opposite directions), the body 26 of which is carried by the frame 12, and having an actuating rod 25 movable in axial translation in one direction or the other relative to the frame 12, and a connecting rod 24 connecting the arm 22 and the actuating rod 25.
• the arm 22 extends generally parallel to the sewing direction D, above the work-holding plate 13, at least substantially in a horizontal direction .
• the downstream end 29 of the arm 22 is articulated to the frame 12 of the machine, by articulation means, in a manner adapted so that the arm 22 can pivot around a vertical axis 27 and around an axis horizontal transverse 28.
• the actuating member 23 is for example a double action pneumatic cylinder whose body 26 is carried by the frame 12 in an at least substantially vertical direction, slightly inclined downward and upstream in the example shown.
• the upstream end 30 of the arm 22 carries the upstream pressing member 10 with the guide piece 14 of the tension thread 8.
• the free end of the actuating rod 25 of the actuating member 23 is adapted to be able to exert, in the normal position, a pressing pressure on the arm 22 in the direction of application of the pressing member upstream 10 on the part 1 to be sewn, that is to say downwards and towards the work-holding plate 13.
• the end of the actuating rod 25 indeed comes to bear against the arm 22 when the rod actuation 25, oriented downward relative to the body 26, is in the fully deployed state.
• the end of the actuating rod 25 is advantageously formed of a flat 31 defining a vertical lateral face against which the articulated arm 22 abuts laterally.
• the actuating rod 25 also limits the possibilities of pivoting of the arm 22, and therefore of the upstream pressing member 10 horizontally towards the frame 12.
• the flat 31 also defines a shoulder which comes to bear on the upper edge 20 of the arm 22 for applying the upstream pressing member vertically downwards as described above.
• the connecting rod 24 has a twist in its longitudinal direction, so as to generate, from a translational movement accompanied by a proper rotation (around its translation axis) of the actuating rod 25, movements lateral displacement of the upstream pressing member 10 by pivoting of the arm 22 about the vertical axis 27, and vertical displacement of the upstream pressing member 10 by pivoting of the arm 22 around the horizontal transverse axis 28.
• the link 24 is connected to the arm 22 by a longitudinal slot 32 formed in this rod 24, in which a slide 33 secured to the arm 22 can slide.
• the slide 33 is for example simply made up of a head screw passing through the lumen 32 and engaged in a corresponding tapping of the arm 22.
• the connecting rod 24 is also fixed integral with the actuating rod 25 by a tight collar 34 by a screw.
• actuating rod 25 rotates on itself around its longitudinal axis.
• This own rotation movement, and the pivoting of the arm 22 about the vertical axis 27 may result from the twisting of the connecting rod 24 and / or be obtained by means 35, 36 of specific guiding in proper rotation of the actuating rod 25 during these translational movements.
• a sleeve 35 is fixed integral with the actuating rod 25 by any appropriate means (keys, radial screws, etc.), this sleeve 35 carries at least one radial stud 51 extending projecting towards the 'exterior and which comes to cooperate with inclined bearing surfaces 52 of suitable shapes formed in a socket 36, itself carried by the frame 12 of which it is integral.
• the actuating rod 25 and its sleeve 35 pass axially through the sleeve 36.
• the stud 51 of the sleeve 35 and the bearing surfaces 52 of the sleeve 36 are adapted to cause a clean rotation of the rod 25 around its axis in one direction or in the other when the latter moves in translation, in one direction or the other.
• the means 22, 23, 24 for supporting the upstream pressing member 10 act, with the guide piece 14, means for releasing the tension wire 8, and are adapted to move transversely, laterally, to the opposite the engine mount 12, and vertically a portion 37 of the tension wire 8 which extends between the downstream drive member 11 and the guide piece 14.
• This portion 37 of the tension wire is that which extends from 'a part immediately downstream of the stitching means 5, 6, 7, up to the downstream drive member 11, and immediately upstream of the stitching means 5, 6, 7, up to the guide piece 14.
• this portion 37 of the tensioning wire is that which extends immediately downstream and upstream from the stitching means 5, 6, 7.
• This portion 37 of the tension thread is that which passes into the zone of action of the stitching means 5, 6, 7, and which is in sewing classes.
• the release means 14, 22, 23, 24 are adapted so that the guide piece 14 can be placed, either in the normal position where it guides the tension thread 8 in the sewing direction D in the passage P as described below.
• Figures 3 to 11 show the upstream pressing member 10 and the guide piece 14 in normal position, the tension wire 8 being normally engaged in passage P defined by the overlock 3 along the edge of the piece 1 to be sewn. From this normal position, and even during sewing, that is to say without interruption of the stitching means 5 to 7, it is possible to place, by actuating the jack 23, the upstream pressing member 10 and the guide piece 14 in the release position (FIGS. 2, 4, 5 and 11). Therefore, the portion 37 of the tension thread 8 extending between the downstream drive member 11 and the guide piece 14 has a lateral and upward inclination relative to the sewing direction D.
• this arrangement in particular avoids the sting of the tension thread 8 by the needle 5 since the entire portion 37 of the tension thread 8 extending upstream to from the downstream drive member 11 is moved laterally and inclined relative to the sewing direction D.
• the tension thread 8 is therefore not ?? by one of the auxiliary threads 4 of the seam.
• FIG. 5 represents the arrangement obtained after forming a few additional overlock stitches, the intersection between the portion 37 of the tension thread 8 and the seam of the overlock stitch 3 being moved downstream, the portion 37 of the tension thread being released laterally from the downstream drive member 11 and from the first sectioning knife 16.
• the portion 37 of the tension thread 8 is released from this first knife 16 which, when actuated as shown in FIG. 5, only cuts the overlock point 3, that is to say - Say that the auxiliary threads 4, to form an end end 53 of the overlock stitch 3 for the piece 1 to be sewn at the end of sewing, and a start end 19 of the overlock stitch 3 for a next piece 1 to be sewn.
• FIG. 6 a subsequent position has been shown in which the upstream portion 37 of the tension thread 8 released outside the passage P of the overlock 3 is brought opposite and in the second cutting knife 17, then cut by this second knife 17
• the upstream pressing member 10 and the guide piece 14 have been brought back to the normal position (by controlling the jack 23 in the direction of descent of the actuating rod 25).
• the stitching means 5, 6, 7, and the drive means 9, 10, 11 are interrupted.
• the part 1 is then provided with an overhanging strand 38 of the tension thread 8 which is left free outside the overlock 3 at the end of sewing.
• the length d2 of this protruding strand 38 depends on the length of the portion of tension wire 8 which has been scrolled downstream from and beyond the second cutting knife 17.
• the piece 1 also includes a protruding strand 18 which was previously formed at the start of sewing, the length d1 of which depends on the distance between the last knife 17 and the first knife 16.
• the second knife 17 is fixed on the machine. so as to allow adjustments of the position of the second knife 17, and therefore of this length dl.
• the second knife 17 is carried entirely (movable blade and fixed blade) by a frame 54 (FIG. 16) which is slidably mounted on a slide 55 extending parallel to the sewing direction D downstream from of the engine mount 12 of the machine to which it is fixed.
• a tightening button 56 with a thumb wheel makes it possible to lock the frame 54 in place on the slide 55 after adjustment.
• the fixed blade of the knife 17 is formed by a plate 57 placed on the work-holding plate 13.
• the frame 54 also advantageously carries a motor actuating member 21 of the knife 17. When the frame 54 is moved along the slide 55, the distance dl is modified while keeping the second knife 17 aligned with the first knife 16 in the sewing direction D.
• the tension of the auxiliary threads 4 of the overlock 3 is simultaneously reduced , in particular at least the tension of the auxiliary thread 4 of the needle, and of the auxiliary thread 4 of upper hook.
• the machine according to the invention is provided with a double-acting actuating member, such as a pneumatic cylinder 39, the actuating rod of which carries at least one shim of thickness 40 adapted to be able to engage. between the pressure washers adjusting the tension of the needle 4 and upper hook threads (figure 1).
• the shim 40 is released from these pressure washers, so that the tension of the wires and that which is obtained in the traditional way by the adjustments made on the machine.
• the actuator 23 for actuating the release means is actuated in the direction of return of the guide piece 14 in normal position
• the actuator 39 carrying the wedge 40 is simultaneously actuated to engage the wedge of thickness 40, in the washers of pressure of the needle thread and of the upper hook thread, and completely relax the auxiliary threads 4.
• the tension thread 8 exceeds the needle 5 towards the motor frame 12 or comes into abutment against this needle 5 and will overtake it on its next ascent. This avoids for sure the passage of the needle 5 through the tension wire 8 and therefore the blocking of this tension wire 8 on the workpiece which would hinder its possibilities of subsequent sliding in the passage P of the su ⁇ et 3.
• These means 41 to 44 are for example constituted by a gantry 41 extending in particular above the work-carrying plate 13 and carrying a vertical column 42 at the lower end of which is fixed a plate 43 provided with means for gripping of the part 1, the assembly being controlled in its movements by a programmable digital system 44 (automaton, computer system, etc.).
• the gantry 41 is adapted to allow movement in translation of the column 42 and of the plate 43 in the two horizontal directions.
• the column 42 and the plate 43 are adapted so that the latter can on the one hand be controlled, relative to the work-holding plate 13, in proper rotation about a vertical axis, and on the other hand be controlled in translations up or down depending on the vertical direction.
• the assembly therefore constitutes a suitable gripping robot programmed to move the part 1 on the work-holding plate 13 of the machine as and when sewing.
• This robot is also suitable for taking a piece 1 from a pile 58 of waiting sewing pieces, and engaging it under the upstream pressing member 10 of the machine at the start of sewing.
• This robot is also programmed to move the piece 1 at the end of sewing by the distance dl + d2, with the tension thread 8 in the second knife 17 as described above, then to place each sewn piece on a stack 59 of pieces sewn.
• the digital system programmable 44 is also programmed to control the various actuating members 23, 39, and the general operation of the machine, in particular the drive means 9 to 11, and the stitching means 5 to 7.
• the plate 43 is provided with means for gripping the pieces 1 making it possible to take one, and only one piece 1 from the stack 58 of pieces to be sewn, then to release the piece 1 on the stack 59 after sewing.
• These gripping means can be produced in any suitable manner, depending on the nature of the parts 1, by suction cup (air suction), by fabric gripping claws (such as the claws reference SCH 20 or ST 36 sold by the Company SOMMER AUTOMATIC (Germany)), by a repositionable self-adhesive, by hooking means such as loops and claws (VELCRO, registered trademark), by static electricity, by pinching ...
• the production and programming of a gripper robot and its associated programmable digital system as described above are well known per se and do not pose any particular difficulties.
• the assembly can be achieved by electric stepper motors, each generating movements, encoders and programming of traditional digital controls.
• the invention can be the subject of several variants compared to the embodiment described above.
• the subsequent overlock stitch 3 drive without tension thread 8 or piece 1 being obtained satisfactorily by at the downstream drive member 11, it is also possible to disengage the tension wire 8 without moving the upstream presser member 10.
• the release means are formed by a horizontal cylinder 45 whose body 46 is carried by the frame 12, and whose actuating rod 47 is connected to a guide eyelet 48 crossed by the tension wire 8.
• This eyelet 48 is disposed, in the normal position, at the downstream outlet of the guide piece (tube) 14 carried by the upstream pressing member 10.
• the eyelet 48 is nevertheless arranged upstream of the stitching means 5, 6, 7.
• the 48 guide is thus itself a lateral guide piece of the tension wire 8 which is disposed downstream of the upstream pressing member 10 and the guide piece 14 which it carries, and upstream of the stitching means 5, 6, 7, so that this guide eyelet 48 laterally displaces the portion of the tension thread 8 extending between the downstream drive member 11 and the outlet of the guide piece 14 carried by the upstream pressing member 10.
• the jack 45 is adapted to be able to place the eyelet 48, either in the normal position opposite the outlet of the guide piece 14, or in a laterally released position in which the eyelet 48 is laterally spaced opposite the frame 12 and beyond the upstream pressing member 10, to laterally move the portion 37 of tension wire 8 ( Figure 18).
• the upstream pressing member 10 must have an appropriate shape to allow the movements in transverse translation of the actuating rod 47 for actuating the jack 45 and the eyelet 48.
• the upstream pressing member 10 is carried by a support arm 49 which must be disposed sufficiently upstream so that the eyelet 48 moves downstream of this support arm 49, the tension thread 8 not passing upstream of this arm 49 of support.
• the upstream pressing member 10 is carried by a fixed support arm 49, by built-in protractor 12, and the articulated arm 22 carries a guide piece 61 in the form of a tube, similar to the guide piece 14 of the first variant, but which is dissociated from the upstream pressing member 10.
• the arm 22 is controlled in its movements by the jack 23 and the connecting rod 24 as described for the first variant.
• the shape of the upstream pressing member 10 is slightly modified to extend more upstream of the side cutter 2 and laterally on the side of the frame 12 than in the embodiments previously described.
• the variants of FIGS. 18 and 19 allow the tension thread 8 to be released transversely while retaining the guidance of the piece 1 to be sewn by the upstream pressing member 10. It is thus possible in particular to form loops of the tension thread in the running part of sewing by ensuring precise guidance of the piece 1 to be sewn by the upstream pressing member 10.
• the stitching of the tension thread 8 by the needle 5 during the lateral displacement of the guide piece 14, 48, 61 is almost improbable, and can be avoided by appropriate synchronization of the actuating member 23, 45 with the movements of the needle 5.
• an eyelet 48 for guiding the tension wire 8 is, as in the variant of FIG. 18, crossed by the tension wire 8 and disposed downstream from the downstream outlet of the guide piece 14 carried by the upstream pressing member 10 and upstream of the means 5, 6, 7 for stitching.
• This eyelet 48 is formed at the free end of a rod 63 articulated freely pivoting about a horizontal axis 64 parallel to the longitudinal direction D of sewing at the end 65 of a screw / nut system 66 carried by the rod actuating 67 of a first horizontal jack 68 with double action, the body 69 of which is fixed to the frame 12.
• the screw / nut system 66 allows the length between the end 65 carrying the axis 64 of articulation of the the rod 63 and a support arm 70 carried by the actuating rod 67.
• the support arm 70 carries the body 71 of a second double-acting jack 72, the actuating rod 73 of which is articulated to a rod 74 secured to one another, in rotation about the axis 64, of the rod 63 carrying the eyelet 48.
• the second cylinder 72 is therefore carried by the actuating rod 67 of the first cylinder 68.
• the rod 74 extends upward, forming an angle of approximately 90 ° with the rod 63 carrying the guide eyelet 48.
• the actuating rod 67 of the first cylinder 68 is retracted and the actuating rod 73 of the second cylinder 72 is deployed.
• the rod 63 extends at least substantially horizontally, and the guide eyelet 48 and the tension thread 8 are in the normal sewing position.
• the second cylinder 72 is actuated to deploy its actuation rod 73, which returns the eyelet 48 to the normal sewing position, and the tension thread 8 is reintroduced into the passage P.
• the loops 62 thus formed extend at least substantially vertically upwards from the part 1, and are thus preoriented. This variant is more particularly applicable in the case of an elastic tension wire 8.
• the loops 62 regularly distributed along the edge of the piece 1 make it possible to garnish and dress with this piece 1 an object provided with hooks or hanging studs, the piece 1 being stretched thanks to the tension wire 8.
• the tension wire guide piece 8 can be arranged between the support 49 of the upstream presser foot 10 and the engine mount 12, or immediately upstream of the upstream presser foot 10, it is possible to program an upward movement of the upstream presser foot 10 simultaneously with the lateral movement of the workpiece guide which will then pass under this upstream presser foot 10.
• the machine according to the invention can be easily obtained by simple modification and addition to a traditional shaving serger sewing machine such as that described and represented in EP-0 223 312 and / or US Pat. No. 4,732,097. It suffices to modify the support device for the upstream presser foot 10, and to add thereto the downstream drive member 11 with its associated drive means, by coupling it to the means for driving the lower feed dogs 9.
• the invention can be the subject of other alternative embodiments.
• the invention is applicable with other sewing stitches than an overlock and therefore to other machines than overlockers, as soon as the sewing stitch forms a passage in which a tension thread can be inserted.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Sewing Machines And Sewing (AREA)
• Details Of Garments (AREA)

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• 1997
  • 1997-07-15 FR FR9708952A patent/FR2766213B1/fr not_active Expired - Fee Related
• 1998
  • 1998-07-09 WO PCT/FR1998/001491 patent/WO1999004079A1/fr active IP Right Grant
  • 1998-07-09 CA CA002295164A patent/CA2295164C/fr not_active Expired - Lifetime
  • 1998-07-09 ES ES98937600T patent/ES2174464T3/es not_active Expired - Lifetime
  • 1998-07-09 AT AT98937600T patent/ATE214748T1/de not_active IP Right Cessation
  • 1998-07-09 JP JP2000503279A patent/JP4022043B2/ja not_active Expired - Lifetime
  • 1998-07-09 EP EP98937600A patent/EP1000189B1/fr not_active Expired - Lifetime
  • 1998-07-09 US US09/462,596 patent/US6196148B1/en not_active Expired - Lifetime
  • 1998-07-09 DE DE69804316T patent/DE69804316T2/de not_active Expired - Lifetime
  • 1998-07-09 PT PT98937600T patent/PT1000189E/pt unknown
  • 1998-07-09 DK DK98937600T patent/DK1000189T3/da active
  • 1998-07-09 AU AU86340/98A patent/AU8634098A/en not_active Abandoned

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